With the boom of various emerging data applications, customs' demands for high-definition video and high-speed data services have been increasing rapidly, and the demand for network bandwidth also increases accordingly, which makes more urgent the construction of the broadband optical fiber access network. The metropolitan area network and the backbone network need a higher speed. The optical network will be developed toward IP-orientation, integration of more business, flexibility of resource allocation, and higher reliability, and a high speed and a large capacity will be goals of development of the future optical transmission network. The 100 Gbit/s communication system has been gradually commercialized, and the 400 Gbit/s communication system has become an inevitable development trend. Increasing of the transmission rate has put forward higher requirements on the laser used as a light source for the communication. If a traditional fixed wavelength laser is used, more than one laser is needed, which increases the cost of the system and limits expandability and flexibility of the optical network. If a tunable laser is used, the laser may include a reduced number of modules, has a decreased cost, and functionalities of the network may be enhanced. So, the tunable laser is the best choice for the light source in a high-speed coherent communication system. The tunable laser may be implemented as a monolithic integration laser, an external cavity laser, a hybrid integration laser, or a laser of other forms.
At present, the 100 Gbit/s high-speed communication system often adopts a multi-channel tunable laser with a C-band output wavelength in consistence with the ITU-T standard wavelength and a channel spacing of 50 GHz. Such a laser usually has about 100 channels, and depending on system requirements, each channel of the laser needs to be tested for varieties of output characteristics such as output power, output wavelength, side-mode suppression ratio and the like, so that the testing work of the laser is very tedious. The conventional approach is to use a plurality of test meters, such as a power meter to measure the output power of the laser, a wavelength meter to measure the output wavelength of the laser, a spectrometer to measure the side-mode suppression ratio of the laser, and the like, which causes many problems in the test process, for example, a large number of test meters, high cost, and time consumption. In allusion to these problems, the present invention proposes a multi-channel tunable laser testing device which integrates a plurality of performance testing functions for the tunable laser, and accordingly the cost of the testing system is decreased, the number of testing meters is reduced, and it may be operated easily. By control of a computer, a laser automatic testing system may be implemented, which can effectively improve the testing efficiency and may be used in batch production of the tunable lasers.